Tag Archives: stats

Summer Nights are Getting Warmer Across the US

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Summer is the time of year when warm temperatures are expected. As our climate changes, however, the season is getting even hotter, especially at night.

Since 2010, according to NOAA, there have been 34% more record-warm low temperatures set than record-warm high temperatures. Nationally, summertime lows have increased an average of 1.8°F since 1895, according to an analysis by Climate Central, a nonprofit science news organization. The southwestern part of the country has seen the greatest warming, with Reno and Las Vegas, Nevada showing an increase of 16.9°F and 9.1°F respectively. Not far behind are El Paso, Texas at 7.7°F and Salt Lake City, Utah at 6.6°F.

In addition to climate change, land use issues also play a role in our warming nights. Paved surfaces hold more heat than vegetated ones, so cities tend to be hotter than rural areas, particularly during the overnight hours. This is known as the urban heat island effect.

When temperatures do not significantly cool off at night, people do not get a chance to recover from the heat of the day. This can cause serious health concerns, especially for young children, the sick, and the elderly. Warmer nights also drive up energy bills, as people with air conditioning units use them more. This in turn, if they are powered by fossil fuels, adds even more greenhouse gases to the atmosphere.

Credit: Climate Central

July 2019: Tenth Hottest July on Record for NYC

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July is usually the warmest month on the calendar for New York City, but this year it was especially hot. In fact, it tied July 1949 as the city’s tenth warmest July on record.

In all, it produced 26 days with above-average readings, including ten days in the 90s. Four of those days came during a heatwave in the middle of the month when the air temperature reached 95°F and the humidity made it feel well above 100°F.

Overnight lows were also mostly warmer than normal throughout the month. On July 20, the mercury only fell to 82°F, setting a new record warm low temperature for the date. In the end, the city’s mean temperature for the month was 79.6°F, which is 3.1°F above average.

It is important to note that four of the city’s ten warmest Julys on record have now occurred since 2010. The warmest was July 1999, when the average temperature for the month was 81.4°F.

This July was also above average in terms of precipitation. With several intense thunderstorms rolling through the area, a total of 5.77 inches of rain was measured in Central Park. The city, on average, gets 4.60 inches of rain for the month.

Credit: The Weather Gamut

First Heatwave of 2019 Brings Extreme Temperatures to NYC

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A heatwave gripped a large swath of the eastern United States this weekend. For many areas, the temperatures were extreme.

The threshold for what constitutes a heatwave varies by region, but here in the northeast, it is defined as three consecutive days with temperatures reaching 90°F or higher. In New York City, the official temperature in Central Park reached 91°F on Friday, and 95°F on both Saturday and Sunday. Overnight lows were also well above average. In fact, on Saturday, the temperature only cooled down to 82°F, tying the record warm low termperature for the date that was set in 2015.

When the humidity was factored in, it felt even hotter. The heat index ranged from 105°F-110°F.

The city’s airports, LGA and JFK, both in the borough of Queens, posted record high temperatures over the weekend, according to the National Weather Service. JFK hit 99°F on Saturday, breaking the previous record of 96°F that was set in 2013. On Sunday, LGA reached the century mark (100°F), tying the high-temperature record for the date at the site that was set in 1991.

The cause of this exceptional heat was two-fold. First, a large area of high pressure sitting over the central US was pumping hot air from the southwest toward the northeast. At the same time, a strong Bermuda High off the east coast was pumping warm, moist air from the Gulf of Mexico into the region. Together, they made it dangerously hot, which is why the NWS issued an excessive heat warning for the city. It is also why several outdoor events around the Big Apple were canceled, including the NYC Triathlon.

The hottest day ever recorded in New York City occurred on July 9, 1936, when the air temperature hit 106°F in the shade. The city’s normal high temperature this time of year is 84°F.

June 2019: Warmest June on Record for Planet Earth

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Our global temperature continued its upward trend last month with June 2019 marking the warmest June ever recorded on this planet.

According to the State of the Climate report by NOAA’s National Centers for Environmental Information, Earth’s combined average temperature for the month – over both land and sea surfaces – was 61.61°F. That is a staggering 1.71°F above the 20th-century average and 0.04°F above the previous record that was set in 2016.

June 2019 also marked the 414th consecutive month with a global temperature above its long-term norm. That means the last time any month posted a below-average reading was December 1984. Furthermore, nine of the ten warmest Junes have occurred since 2010. June 1998 is the only year from the last century on the top ten list and currently ranks eighth.

While heat dominated most of the planet this June, some places were particularly warm, including Europe, parts Russia and South America, as well as Alaska. In fact, Europe posted its warmest June on record and Alaska had its second warmest June since statewide record-keeping began there in 1925.

For the contiguous US as a whole, this June was close to average and ranked in the middle third of the national record. To put this disparity into context, consider that the United States constitutes less than 2% of the total surface of the Earth. This detail also highlights the fact that climate change is a complex global phenomenon that involves long-term trends more than the short-term weather conditions that are happening in any one part of the world.

Year to date, the first six months of 2019 tied with the first half of 2017 as the second warmest such period of any year on record. At this point, it is very likely that 2019 will finish among the top five warmest years on record. Global temperature records date back to 1880.

June 2019: Earth’s Warmest June on Record. Credit: NOAA

Swamped by Barry, Arkansas Sets New State Tropical Rainfall Record

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Hurricane Barry made headlines for making landfall in Louisiana over the weekend, but its torrential rain made history Arkansas this week.

According to the NWS, the remnants of the moisture-laden storm dumped 16.59 inches of rain in Dierks, Arkansas, setting a new tropical rainfall record for the state. The previous record of 13.91 was set in Portland, AR during Tropical Storm Allison in 1989.

Arkansas is the fifth state to set a new tropical rainfall record in the last two years. The other four include Texas, Hawaii, North Carolina, and South Carolina.

These types of extreme rain events have been happening more frequently in recent years and most experts see a link to climate change. As the atmosphere and oceans warm, storms are able to carry more moisture, and therefore drop more rain.

Credit: The Weather Gamut

June 2019: A Soggy Start to Summer in NYC

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June 2019 was another month of wild temperature swings in New York City. Highs ranged from an unseasonably cool 65°F to a balmy 91°F. In the end, however, the cold and warmth balanced each other out. The city’s mean temperature for the month was 71.7°F, which is only 0.3°F above average.

In terms of precipitation, the city was unusually wet. Overall, 13 out 30 days posted measurable rainfall that added up to 5.46 inches for the month. While that is a soggy statistic, it was not the wettest June the city has seen. That dubious honor belongs to June 2003 when 10.26 inches of rain was measured in Central Park. The city, on average, gets 4.41 inches for the month.

Credit: The Weather Gamut

First 90°F Day of the Year for NYC

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The heat is on in New York City! The temperature in Central Park soared to 91°F on Saturday, marking the city’s first 90°F day of the year.

While readings in the 90s are not uncommon for the Big Apple during the summer months, they typically premiere earlier in the season. On average, the city usually sees its first 90°F day by the end of May.

According to NWS records, the city’s earliest first 90°F day was April 7, 2010, and its latest was July 26, 1877.

For the season as a whole, NYC typically gets an average of 15 days with temperatures reaching 90°F or higher. By month, that usually breaks down as May (1), June (3), July (6), August (4), and September (1). That said, every year is different. The most 90°F days the city experienced was 37 during the sweltering summer of 2010.

Credit: Melissa Fleming

Summers are Getting Hotter in the US

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Summer is the warmest part of the year with high sun angles and long daylight hours. But, as our climate changes, the season is getting even hotter.

Across the contiguous United States, summer temperatures have increased an average of more than 2°F over the past fifty years, according to Climate Central, a non-profit science news organization. The western and southwestern parts of the country have seen the fastest seasonal increase, with places like Boise, ID, Las Vegas, NV, and McAllen, TX each warming more than 5°F since 1970.

Soaring temperatures can pose a risk to human health and cause energy costs to skyrocket as people try to beat the heat.  They can also lead to drought and threaten agricultural production.

Reducing global greenhouse gas emissions, which are causing the atmosphere to warm, can minimize many of these impacts. On a local level, adaptation measures are also important. In urban areas, which tend to heat up quickly, planting more trees can help keep neighborhoods cooler during the increasingly intense heat of the summer months.

Credit: Climate Central

Earth Posts 4th Warmest May and 2nd Warmest March-May Season on Record

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Our global temperature continued its upward trend last month. May 2019 marked not only Earth’s fourth warmest May but also closed out the planet’s second warmest March-May season on record.

According to the State of the Climate report by NOAA’s National Centers for Environmental Information, Earth’s combined average temperature for May – over both land and sea surfaces – was 60.13°F, which is 1.53°F above the 20th-century average. This May also marked the 413th consecutive month with a global temperature above its long-term norm. That means the last time any month posted a below average reading was December 1984.

The three-month period of March, April, and May – meteorological spring in the northern hemisphere – was also unusually warm. NOAA reports that Earth’s average temperature for the season was 1.73°F above the 20th century average of 56.7°F. That makes it the second warmest such period on record. It is also important to note that the five warmest March-May periods have all occurred since 2015.

While heat dominated most of the planet this season, some places were particularly warm, including Alaska and western Canada. For the contiguous US as a whole, this spring was close to average and ranked in the middle third of the national record.

To put this disparity into context, consider that the United States constitutes less than 2% of the total surface of the Earth. This detail also highlights the fact that climate change is a complex global phenomenon that involves much more than the short-term weather conditions that are happening in any one part of the world.

Year to date, the first five months of 2019 were the third warmest such period of any year on record. Global temperature records date back to 1880.

Credit: NOAA

May 2019: Second Wettest Month on Record for US

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When it rains, it pours! This old adage was proven to be true last month. With national weather data dating back to 1895, May 2019 was the second wettest month ever recorded in the contiguous United States. Only May 2015 was wetter.

According to NOAA, an average of 4.41 inches of rain fell across the lower 48 states, which is 1.50 inches above average. Heavy precipitation was reported from the West Coast through the Mid-West, and into parts of the Northeast. Kansas, Nebraska, and Missouri each experienced their wettest May on record.

This relentless rain caused deadly and destructive flooding in several states along the Arkansas, Missouri, and Mississippi Rivers.

While there were a number of factors that contributed to May’s excessive rainfall, including El Nino, climate change also likely played a part.  As the National Climate Assessment points out, heavy precipitation events are increasing in both frequency and intensity across the United States as the atmosphere warms.

As greenhouse gases heat the atmosphere, the air is able to hold more water vapor. More specifically, according to the Clausius–Clapeyron relation, for every increase of 1°F, the saturation level of the atmosphere increases by about 4%. In other words, warmer temperatures lead to more evaporation from oceans, rivers, and lakes, and therefore more water vapor is available to condense and fall as precipitation.

Sadly, with our global temperature continuing to rise, experts say we should expect to see more extreme rain and flooding events in the future.

Credit: NOAA